Cancer prognosis and statistics

Cancer A~

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As I have mentioned before, cancer has a lot to do with number.  Risk, prognosis, and so on are rooted in some simple types of math.  Statistics are often thought of as cold unfeeling facts that do not help much.  The first part may be true but the last part is far from truth.  However, psychology is very important when people talk about cancer with one another.  statistics (if the numbers are good) help to overcome issues related to bias and personal feeling about things so that we can get a better handle on certain issues related to cancer.  Many of us (if not all) fall into recognizable patterns often; how many times have we heard someone tell us, my friend or relative was cured of this or that.  Most likely we remember that fact and rely on that treatment issue without much thought.  We may even rely on one persons recommendation to take a certain supplement because they swear how he/she has overcome some serious complications etc.  It’s natrual to think like this, but it’s also a bit destructive.  The ‘n’ of one is not a powerful statistic at all.  Anecdotal evidence…many people have told me this or that, is also easy to rely on.  What we miss in the ‘n’ of one or the anecdotal evidence is the others who took the same drug/supplement that had no benefits.  Or we fail to realize that the person who is telling us the evidence is biased or perhaps not accurate at all.  This is often the case for most folks who are promoting self-help, alternative medicines, or supplements…that all too often have little evidence for being effective. 

So what do we do about all of this….well think.  Ask yourself about the evidence before you start buying expensive supplements.  If the person selling you the stuff or your relative who believes in some remedy for the common cold…please ask them to produce some rational evidence to you. 

So what is prognosis?  It is a guess that doctors give that is often based on statistics from a large or even small group of patients who have had the same conditions as you.  More specifically, for cancer patients it is the prediction of the future course and outcome of a cancer and an indication of the likelihood of recovery from that cancer.  So, from this you might guess a few things.  A prognosis is not fact…it’s an educated guess.  A prognosis (an estimate for example of how long you have to live with a particular treatment for example) is limited by the ‘power’ of the number of individuals who have been previously analyzed.  So, if it’s the common forms of breast cancer the prognosis might be really accurate as there is a huge patient number that allow for very good statistical interpretation.  If it’s mesothelioma, a much more rare cancer, the prognostication might not be very accurate.  Furthermore, no two people are alike…our immune systems are different, are genetics are different, and out habits (such as eating, etc.) and thus we might not respond at all like the average patient.  So, a given prognosis is an estimate…but not final or finite.  It is a rough guideline.  Put it this way, if good statistical information is available…why not put some faith in it and listen to the doctor who gives you an estimate about your response?  If the statistical information is weak or based on one person’s advice or anecdotal evidence, why not questions the information and rely less on it?  Keep an open mind but don’t ignore previously recorded evidence.  A good prognosis will boost your confidence and have a positive impact on your thinking and a negative/poor prognosis will sap your confidence and perhaps may even have a negative impact on your health. 

This leads me to my final comment…statistics can be cold numbers that don’t reveal everything.  If the doctor gives you a poor prognostic for your survival with cancer X, you may wish to ask him what he uses for evidence.  How large is the sample size or the trial size that he is using?  He will know that information or can find it fairly quickly.  Do not give up just because you have been told your prognosis is poor.  The evidence behind that prognosis is poor and you may respond differently (the mean may not tell the whole story).  Ask more questions the more negative the news is…you owe it to yourself!!

Ok, I think I will stop now…please do ask me to clarify anything if you wish!  Thanks for reading.  Do look at cancer made simple for more information!!! 

Dr. C

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The placebo effect or the placebo response

Placebo Effect (Doctor Who)

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Evidence-based medicine for all it’s ugly by products, is here to stay.  This means that any therapies/medicines/approaches to helping patients with illness must be proven by outcomes in a controlled and documented manner.  That means just simply saying, ‘see it works’ will not cut it.  Since 1993, when the Cochrane Collaboration was formed and recommended that all studies be conducted as full ‘ Randomized Control Studies’, evidence-based medicine has dominated Western thinking.  Those who have promoted that we treat patients the same way as we have always done without properly conducting trials when possible are of course not happy with this type of medicine.  Those who promote ‘complimenary and alternative medicine or CAM‘ are also not too happy, as many state that the effectiveness of that type of therapy is based on hundreds of years of experience. However, many supporters of CAM have been conducting randomized control trials to address these concerns about real efficacies.  So far, no CAM therapies have been proven effective after these trials are done.

So this is where placebos come in to play.  A placebo is an agent that is given to a patient that does NOT contain the active ingredient or ‘device’ being tested in the experimental arm.  So, if for asthma medication treatment study that could be the inhaled drug albuterol as the experimental agent and inhaled air as a placebo.  A placebo is designed to act as a type of control.  However, it is not a true control as if it is inhaled (even air) it may be perceived to provide some benefit by the patient.  A true control would be non-intervention or nothing.  So inhaled albuterol, inhaled air as a placebo and nothing as a true negative control is a great example of a randomized control trial design.  The patient does not know which one he/she is given (the placebo or albuterol) but will know if they are in the nothing treatment arm. 

This is actually a true study designed to look at the placebo effect.  This particular study published in the New England Journal of Medicine and compared the effects of inhaled asthma drug, placebo, acupuncture, and no treatment conditions.  The interesting thing is that when all of these were compared the placebo, the acupuncture and even the no treatment conditions all showed strong subjective responses.  This means that when patients were asked how these treatments made them feel about their asthma, they were very positive in their answers.  The drug was slightly higher at about 50% subjective responses while the acupuncture and placebo were both at about 45%, not much lower.  The lowest response came from those with no intervention; 21% of those folks felt that no treatment made them feel much better.  Seems good right?  Wow, seems like we can avoid expensive drugs and just take inhaled air or go see an acupuncturist right?

No, it turns out that the second set of data is what really makes people stand up and take notice.  When you actually measure the amount of air that gets in through the lungs (by an accepted lung air measuring medical device) the data looks completely different. When they actually measure physiologic response; ONLY the inhaled drug works well and gives a measurable response.  Whereas all three other treatment (or lack of it) gave the same low response.  So, the body really does react to the drug and only very little to the non drugs (or the placebo effect). There was actually no difference in physiologic or objective responses between the non-intervention or the placebo or acupuncture.  They were the same.  The body derives zero benefit from these as compared to no treatment.  

So, not to trash the CAM believers in any way…this is only one study on Asthma and not the definitive study on all other indications where traditional chinese medicine or other CAMs may have some effects (positive not negative).  But, this is fairly drastic news for those who propose that the placebo effect may explain how CAM works…as the placebo effect (in this case) is a fallacy.  It also underscores something else very important….that is, subjective responses (I feel, he feel, she feels) are very dangerous and recording them may not be the best measurement when looking at medications and treatments.  This is a big issue now?  Do we look at objective or subjective measurements?  For evidence-based medicine, the answer is clearly objective outcomes. 

Thank you for reading…Dr. G Cancer Made Simple  

The war on cancer: 3 challenges

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This blog report is based on Dr. Mukherjee’s NY Times commentary made on July 16th.  To summarize his observations, cancer prevention faces an uphill battle due to three major forces; science, politics and society.

To explain this he brings up the highly contentious issue of cell phone usage and it’s link to cancer.  Scientifically, there is little proof that electromagnetic radiation that is emitted from active connections from cell phones lead to increased incidences in cancer.  The type of radiation that is emitted is so weak that it has never been shown in any experiments of any kind to damage DNA (a fundamental hallmark of cancer development).  However, an interphone study that was conducted that asked people to state their cell phone usage patients (low, medium or high) and then followed them for a period of time to look for cancer occurrence (brain cancer), found a link.  Other studies have since found that what people perceive as their phone usage is frequently very different from reality (that is of their actual usage).  So, this study is probably not very accurate.  Furthermore, it is easy to ask what the incidence of cancer was before the adoption of cell phone and after.  When one does that there is NO correlation at all to phone usage and cancer incidence.  However, this has not stopped the WHO to place cell phone usage in the ‘possible carcinogen’ category.  This may not be a mistake itself, but reminds us that despite science policy and warnings will still be made. 

Another issue that focused on politics was focused on formaldehyde.  This example is the exact polar opposite of the above one.  Here, it is well established that formaldehyde in the laboratory caused DNA damage that leads to cancer.  Furthermore, those who work in the formaldehyde industry do develop certain cancers at higher incidences (at least certain kinds of blood cancers).  These studies occurred over 30 years ago and only now did the National Toxicology Program only now issued a statement calling this chemical a carcinogen.  The large reason behind this was that science was finally placed before politics.  Lobbying efforts by companies who make the chemical have fought long and hard to stop any major governmental organizations from labelling this chemical as such.  They, of course would prefer if nothing negative is ever said about any of their many chemical/compounds/etc that make them billions of dollars.  I would bet my money on the fact that most if not all of the senior lobbyist and CEO’s of these chemical companies that make formaldehyde have not worked with the raw processing of this drug and certainly don’t suffer from the carcinogenic events (if they or their families did, I assume they might not put profits before safety). 

Finally, despite strong evidence from the 50’s onward, tobacco companies have been doing everything they possibly can to prevent any rules that are passed that might negatively impact sales.  Historic and unprecedented/massive lawsuits against the major tobacco companies did curtail the sales of cigarettes for some time but they seem to have been on the rise again.  Australia has just enacted some of the toughest laws on cigarette packaging in the world.  The US has just adopted some strict guidelines that require that graphic consequences of cigarette smoking be shown on the cartons despite huge resistance by the industry.  It has been shown that plain packaging and ‘gross imaging’ might just dissuade non smokers to avoid the habit causing agents.  The cost to health and healthcare is too great to ignore and the link of smoking to cancer is too great to ignore! 

This summarizes what was written.  Science should triumph over lobbying efforts to reveal truth to Americans (and to those living in all countries), politics should not be allowed to dominate over policies regulation safety, and social norms (such as smoking) should be kep in check by aggressive policies to assist people avoid bad habits. 

 Thanks….Dr. C Cancer Made Simple!

Old drugs get a new lease on life: cancer!

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When drug companies make new drugs they often spend million and millions of dollars on them.  Due to regulatory issues, new drugs can only be used for one very specific purpose (that at which is was designed and tested for).  However, if the drug is included in the treatment cycle and FDA approved it can ear a company billions of dollars in income.  As you might imagine the incentive to discover new areas of treatment for the new drug is huge.  This is not a bad thing.  There are conditions here one’s immune system is too active and needs to be suppressed.  For example, for transplantation where a donors organ or blood is put into a patient, large amounts of immunosuppressant drugs are used.  These drugs often inhibit the growth or activation of immune cells in the patient.  It turns out that the very same pathways that some of these drugs work in blocking the immune system also work fairly well in blocking cancer cells.  This is where the link is now being pursued by many drug companies.  I will just bring up one example here below but in the future I will introduce other examples.

Recently, Novartis (a big pharmaceutical company) had good success with an immunosuppressant for Breast Cancer.  The drug Afinitor (R) is a type of drug known as Everolimus which was originally designed to block a protein pathway in the cell known as MTOR.  This pathway if blocked prevents activation and proliferation of T cells and is thus acts to prevent immune responses.  Over the years it has also been approved by the FDA to be used to treat late stage kidney cancer, certain metastatic pancreatic cancers and a few other conditions. 

Recently, ver strong clinical data has encouraged the maker of Afinitor (R), Novartis to file for worldwide approval for the use of this mTOR inhibitor in breast cancer patients.  Phase III clinical trials with 700 patients have shown that patients who took this drug plus a hormone inhibitor in advanced breast cancer settings had delayed tumor growth in comparison to estrogen inhibitor therapy alone.  This combination of the two drugs allowed patients who had breast cancer delay their treatment with chemotherapy and slows down the hormone resistance that develops after a time in many of these women.  If awarded, this drug will make over a billion dollars for Novartis. 

So, this is just one example of re-use of a drug that had once been used only for inhibiting the immune system and now used in breast cancer.  It’s an example of an old drug with a new target.    

Thanks …Dr C

Cancer Made Simple

2011 Cancer Stats

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Just a quick update for you stats junkies on the status of cancer deaths and incidences for 2011. 

The estimated number of Americans (sorry the US has some of the best stats out there and is upfront about publishing those numbers) living with cancer today in 2001 is about 11.7 million.  This number is actually a bit misleading as it estimates the total number of people who had cancer (either currently or previously in 2007).  Some of these folks have died of cancer, dies of other causes, or are still alive today (with or without cancer).  However, the number of new cancer cases for 2011 is estimated to be about 1.6 million people.  Thus, cancer deaths and new cancer cases have away of balancing each other out (not always evenly).  About 572,000 people are expected to die of cancer this year. 

Men have about a 1 in 2 lifetime risk in developing cancer while women have about a 1 and 3 chance.  Much of that has to do with cancer from smoking which up until the 80’2 was mostly a problem for men.  In fact, in 2011 cancer related complications from smoking is estimated to kill about 171,600 people.  This is sad as this type of cancer is preventable.  This will change as the women who started smoking in large numbers after men (late 70’2 and further) will soon start to see the delayed increase in lung cancer rates. 

Other preventable cancers (related to obesity, poor nutrition, and infectious agents such as HPV) will result in about 572,000 deaths. It is sad as many of these can be prevented by improving diets, exercising, and lifestyle changes such as smoking cessation and reduced alcohol consumption (easier said than done).  2 million skin cancers are detected annually and many of these can be prevented by appropriate skin care products or a reduction in prolonged exposure.  Many of these cancers are not lethal (if they are detected early the success rate of survival is high) but costs add to ever-increasing health care  burdens. 

Today, heart disease is the biggest killer of Americans…this is followed by cancer deaths at number two.  Today, one in four Americans can be expected to die of cancer.  The typical age of developing cancer is about 55 (in fact, 78% of all cancers are detected at that age or older).

However, as cancer becomes more frequent it is important to ask what is our overall survival rates for those with cancer on average.  The most up to date 5 year survival rates for people with cancer (all forms of cancer combined) is about 68%.  That has improved from a previous rate of about 50%.  However, it is important to note that these numbers are very different from one cancer to another.  As we catch cancer earlier we are able to treat it better.  As treatments improve for some cancers, people are able to survive longer. 

The top ten cancer killers are Lung, Prostate, Colon, Pancreas, Liver, leukemia, esophagus, Bladder, Lymphoma, and Kidney (in men).  In women the second cancer killer is breast instead of Prostate and Ovary, Uterine, and Brain cancers appear on the top ten list. 

Anyhow, I will stop at this and recommend that you read the Cancer Facts and Figures 20011 from the American Cancer Society which is available online.

Thanks, Dr. C

Cancer made Simple